Quantcast

How is this compound Meso?

This forum made possible through the generous support of SDN members, donors, and sponsors. Thank you.

skyisblue

Full Member
10+ Year Member
Joined
Dec 26, 2006
Messages
430
Reaction score
0
According to my book, this molecule is considered meso because there's a plane of symmetry slicing between the H and OH group at the top.

BUT, I don't think this molecule can be meso because the H and OH group are not only NOT identical but they don't even match up in a mirror reflection.

What do you guys think?

Plus, let me know if you guys can't see where the dashes, solid lines and wedges are.....I need a new camera. :laugh:
 

Attachments

  • meso.JPG
    meso.JPG
    4.1 KB · Views: 102
B

BodybldgDoc

According to my book, this molecule is considered meso because there's a plane of symmetry slicing between the H and OH group at the top.

BUT, I don't think this molecule can be meso because the H and OH group are not only NOT identical but they don't even match up in a mirror reflection.

What do you guys think?

Plus, let me know if you guys can't see where the dashes, solid lines and wedges are.....I need a new camera. :laugh:

It is a meso compound and it is also achiral. If you draw it out in the form of a fischer projection, you would be able to see it much better.
 

Nowhat14

Full Member
10+ Year Member
5+ Year Member
Joined
Mar 5, 2007
Messages
102
Reaction score
0
expand CH2OH on the right side and see how it's identical to the left side. And it's really like OH and H that divides right and the left....I think
 

skyisblue

Full Member
10+ Year Member
Joined
Dec 26, 2006
Messages
430
Reaction score
0
It is a meso compound and it is also achiral. If you draw it out in the form of a fischer projection, you would be able to see it much better.

Everything looks like a mirror image of the other except for the H and OH group on top. Yes, that is where the plane of symmetry splits the molecule.

I don't understand because having a plane of symmetry means that one half is a MIRROR image of the other half. Yet, how can H be a mirror image of OH? They are two totally different substituents.
 

Nowhat14

Full Member
10+ Year Member
5+ Year Member
Joined
Mar 5, 2007
Messages
102
Reaction score
0
I think you are cutting H and OH molecules in half. resulting half of H molecule and half of OH molecules. Not H and OH.
 
B

BodybldgDoc

Everything looks like a mirror image of the other except for the H and OH group on top. Yes, that is where the plane of symmetry splits the molecule.

I don't understand because having a plane of symmetry means that one half is a MIRROR image of the other half. Yet, how can H be a mirror image of OH? They are two totally different substituents.

this is why i said draw it out in fischer projection. If you look closely at the wedges and the dashed lines and you draw a line down the middle where it splits the molecule there is a mirror image because all the H's line up on the same side and the OH's line up on the other side. Ignore the H and OH on top and focus on the plane of symmetry.
 
Top